An organic sulfur material comprising carbon, hydrogen, oxygen, and sulfur as constituent elements, and having peaks in the vicinity of 482 cm−1, 846 cm−1, 1066 cm−1, 1279 cm−1, and 1442 cm−1 in a Raman spectrum detected by Raman spectroscopy, the peak in the vicinity of 1442 cm−1 being most intense, has a high capacity and high heat resistance, although a liquid organic starting material is used.